- Skin examination: Skin must be examined for the neurocutaneous markers of TSC.
- Signs of elevated ICP: The examination should look for signs of elevated ICP such as papilledema and sixth nerve palsy.
- Routine tests: No abnormal findings are expected.
On CT scan and MRI, subependymal nodules appear as small, nonobstructing, subependymal nodular lesions. They can occur in any ventricle (5). SEGAs, by contrast, appear as moderate to large-sized subependymal or intraventricular masses that are located near the foramen of Monro. They demonstrate serial growth (5).
CT Scans: SEGAs
- Isointense: SEGAs appear as an isointense intraventricular mass with peripherally located dense nodular calcifications adjacent to the foramen of Monro.
- Large: They are usually larger than 1 cm by the time of diagnosis.
- Enhance: Enhancement is intense and homogeneous (differentiating feature from subependymal nodules) (10, 13, 22).
- Other lesions seen: Usually, other subependymal nodules, tubers, or parenchymal calcifications are also seen.
- Hydrocephalus: Accompanying hydrocephalus may be present.
- T1-weighted images: The lesion will have a mixed hypointense-to-isointense heterogeneous appearance. Intense but nonhomogeneous enhancement may be seen after contrast administration.
- T2-weighted images: Besides hyperintense foci, hypointense areas and strongly hypointense zones due to calcifications are seen, giving the tumor an overall heterogeneous appearance.
- Cortical tubers: Cortical tubers are commonly present in these patients and are better seen with MRI than with CT (2, 8, 22).
Nuclear Medicine Tests
- None indicated
- None indicated
- Useful for following patient: Neuropsychology can be helpful as a baseline evaluation of memory and intelligence when following small- or moderate-sized lesions. After surgery these tests can be used serially during postoperative follow-up visits and for prognostication.
Correlation of Tests
- Decline in cognition: A decline in memory, behavior and/or intelligence may indicate involvement of the fornix and the limbic pathways by the tumor. Improvement in these findings would be helpful as markers of recovery in the follow-up period as well as for prognostication.
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